The wait is over. The NCAA tournament is finally here! Before you fill out your bracket, let's review the biggest takeaways from Selection Sunday and warm up with five questions about the bracket.

Villanova, Gonzaga, North Carolina and Kansas earned No. 1 seeds. But a top billing is rarely a guarantee of tourney success. And with a field considered more wide open than in recent years, anything can happen over the next month.

It's time for your voice to be heard. What do you think about the field of 68?

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Illinois State was left unhappy, without a tournament bid, as was Syracuse coach Jim Boeheim, who pointed out the Orange's three wins over top-10 RPI teams. A number of other teams, from TCU to Indiana to Monmouth, felt they had solid cases for inclusion.

Based on strength of record, some feel that Vanderbilt and Michigan State might have gotten too generous a seed, if they deserved one at all. One can also make a case against the last four at-large bids -- Providence, Kansas State, Wake Forest and USC.

Vermont is back in the fold, which inevitably leads us to fuzzy memories of T.J. Sorrentine draining 3s "from the parking lot." Same for Princeton -- always a threat with its long history of upsets and close calls by way of the backdoor. Middle Tennessee, which as a No. 15 seed upset Michigan State last year, is also back. Will giants be slain again? ESPN's Peter Keating and John Gasaway name Vermont, Middle Tennessee, Princeton, Nevada and UNC Wilmington among the best picks for a first-round upset.

Who enters the Big Dance with the most momentum? Defending national champion Villanova won the Big East tournament, which is something the Wildcats didn't do last year. Duke had to beat Louisville, North Carolina and Notre Dame to win the ACC tournament. Arizona knocked off UCLA and Oregon to win the Pac-12 tourney. Big 12 tourney champ Iowa State has won nine of its last 10. And you can never forget about SEC champ Kentucky, which has won 11 straight.

A top seed is hardly a guarantee of success beyond the tournament's first weekend. Since 2008, when all four No. 1 seeds reached the Final Four, more than one top seed has reached the national semifinal just twice -- in 2009, when North Carolina grabbed its second national title in five seasons, and 2015, when three No. 1 seeds won their regions.

Now that you've warmed up with our five key questions, it's time to fill out your bracket in Tournament Challenge. Who'll make the Final Four and cut down the nets on April 3? Submit your picks before Thursday!